COMET IKEYA-ZHANG

Otherwise known as C/2002 C1, this comet was jointly discovered by Japanese and
Chinese comet hunters in late January 2002. It reached perihelion on the 18th March 2002
at a distance of 0.49 Astronomical Units from the sun. A feature of its spatial
relationship with the Sun and Earth meant that when at its brightest it never achieved an
elongation from the sun of more than 30º. Hence it was always close to the horizon when
it was at its brightest and the sky darkest. Nevertheless during April as it moved north
it became circumpolar from the latitude of Scotland achieving a good altitude above the
horizon before morning twilight. Viewed in binoculars or a small telescope from a darker
sky location it was a splendid object.

Of particular interest were the changes in the tail's
appearance during March and April- from fan-shaped to needle as the dust tail lost
intensity.

The comet seen in twilight in the constellation
of Pisces on the 12th March when it was around 4th magnitude. Mars is the bright red
object upper left and Aries is prominent above. Five minute exposure through a 58mm lens
at f/2. Note the tail stretching for a few degrees towards the upper left.

Imaged again on the 12th March. Five minute
exposure through a 200mm lens at f/3.5.

Imaged on the 1st April when about mag 3.5. The faint
dust tail curves away to the upper left and the blue gas tail stretches away for 6 to 8
degrees (beyond the top of the frame!); 5 min exposure through a 58mm lens at f/1.4. M31
is to the right.

Very wide angle view against the back drop of the
Milky Way. Imaged on the 6th April after its passage by M31; 10 min exposure through a
16mm lens at f/2.8.

Imaged on the 6th April; 10 minute exposure through a
58mm lens at f/2.

Imaged on the 6th April through a 200mm lens at
f/3.5; five minute exposure.

Imaged on the 20th April during an auroral display
through a 180mm lens at f/2.5; 7 min exposure. Note the change in the appearance of the
comet's tail since 6th April.